Hello, I just moved into a new old house and I am experiencing problems with my washing machine that are related to an expected plumbing issue. The issue is that my washing machine is causing my clothes to smell very damp and musty despite the fact that they were washed and dried. I believe that the cause is that the washer no longer discharges all the water because the drain pipe is above the washer and the weight of the discharged water is forcing some of the water back into the washing machine. After a washing cycle has ended, there is still water in our front loading machine. At our previous address where the sewage pipe was under the basement slab, this was never an issue. The drain hose comes out of the back of the washer and attaches to a hose nipple with a hose clamp approximately 3’ above the washer. The nipple is connected to 1-1/2’ PVC pipe. The pipe then travels upwards another 6” at a 45-degree angle into a 45-degree fitting. The pipe then travels across the ceiling about 5’ and then turns 90-degrees into the next room. The pipe travels about 15-20’ across the next room when it goes through a 45-degree “Y” fitting down into the sewage main which is a 4’ PCV pipe about 4’6” above the basement floor.

One solution that I thought would work would be to discharge into a 50 GAL drum and use a sump pump to force the water up, then through a check valve, and across the basement and then down into the sewer pipe. An alternative to the drum would be a sump pump basin could be installed into a cut hole in the floor and a sump pump could do the work. Both of these solutions are expensive for me and will not work well in my basement because of space constraints or safety issues with the basin lid being in the floor in the center of the doorway in to the next room. Someone at Lowe’s suggested that I route 2” PCV from the back of the washer to the sump pump and let the discharge water get pumped out into the city pipes which are underground in my area.

I’m not too happy about having working PCV pipe on my floor but at least I will not stink!

Chances are good that your discharge pipe is back siphoning about 4 gals of water when it stops draining. Washers are not designed to lift water to ceiling height and your 1.5" pipe is also too small and should be replaced with 2" all of the way. This whole system is way too long and should be disconnected. The drum/sump idea is not my dream fix but it would work.

Simple solution! Install a washer hose check valve,(see image) on the discharge hose and there will be no back drainage. Good luck, TGom